Session: 12-13-01: Heat Transfer in Electronic Equipment I

Paper Number: 166711

Study of Fin Parameters for Heat Pipe in Cubesat Application 

Recent advances in computer technologies and manufacturing processes allow us to assemble highly developed components within a compact body such as small-scale satellites (CubeSats). Avionics installed in satellites generate a considerable amount of heat; in addition, during orbit, satellites are exposed to intense solar radiation ranging from direct sunlight, sunlight reflected off Earth (albedo), and infrared (IR) energy emitted from Earth ¹. Hence spacecraft thermal control is a necessity during the design process.  The main challenge is to maintain the allowable temperature limit of all the spacecraft’s components in all thermal environments it may be subjected to.  Heat pipes are the most common passive thermal management devices used for space application due to their weight penalty, zero maintenance, and reliability ².  Fins are used to enhance heat transfer; for instance, fins are added to the condenser part of the heat pipe to improve heat rejection. Moreover, one of the major constraints in space application is weight, and fins can be used to reduce the weight of the thermal control system while maintaining the heat transfer area. R. J. Naumann³ developed a method for optimizing the configuration of a heat pipe radiating fins, in terms of heat rejected per radiating mass.  The objective of the current study is to model, design, and optimize the radiating solid fins attached on the condenser part of the heat pipe to develop a high-performance heat pipe for cooling applications in satellites, taking into consideration two important design parameters: fin weight and geometry, such as, fin thickness, fin width, fin height, and fin spacing. An effort has been made to cover every aspect related to computational optimization of heat pipe radiating fins which is rare in published work.

The numerical study was done using ANSYS Steady State Thermal for copper material. Different fin geometries required different parameter sets; for instance, the rectangular longitudinal fins were parametrized based on three parameters: fin width, fin thickness, and number of fins. In addition, rectangular cross-sectional fins were parametrized with respect to fin width, fin height, fin spacing, and number of fins. Finally, the circular annular fins were parametrized according to fin diameter, fin spacing, and number of fins. For the meshing, different methods, edge sizing, and face meshing were used for different fin geometries. In Steady State Thermal, the setup starts by specifying the material of the geometry (heat pipe and fins). For the present work, a constant temperature boundary condition was applied on the heat pipe inner surface and inlet surface. In addition, a radiation boundary condition was applied on the condenser external surface and the fins. Four different types of meshes comprising 3000 to 270000 nodes were used. The results of net outgoing radiated heat per unit mass against different optimization parameters are discussed. In addition, the net outgoing radiated heat transfer per unit mass for different fin geometries and shapes are analysed and used in the selection of the optimum fin design. For rectangular cross-sectional fins and circular annular fins no improvement has been registered in net outgoing radiated heat per unit mass of condenser/fin system. Furthermore, as fin width increases for rectangular longitudinal fins, trapezoidal longitudinal fins, and triangular longitudinal fins,  elevates. According to the optimization study, increasing the number of fins beyond  n=3 reduces the heat transfer rate per unit mass. It was concluded that increasing T  results in increase of Qnet out/m , since the net outgoing radiation is quadrupled. 

Keywords: Heat transfer, Solid fins, Heat pipe, Finite element method, CubeSat, Space radiator, Numerical Optimization.

References:

1. Gilmore, DG DM. Spacecraft Thermal Control Handbook. Volume I, Volume I,. Vol I.; 2002. http://app.knovel.com/hotlink/toc/id:kpSTCHVFT2/spacecraft-thermal-control

2.          Karam R. Satellite Thermal Control for Systems Engineers.; 1998. doi:10.2514/4.866524

3.          Naumann RJ. Optimizing the design of space radiators. Int J Thermophys. 2004;25(6):1929-1941. doi:10.1007/s10765-004-7747-0

Presenting Author: Md. Islam Khalifa University of Science & Technology

Presenting Author Biography: Dr. Md. Islam is currently an Associate Professor of Mechanical Engineering at Khalifa University of Science and Technology. He received his MSc and PhD from University of the Ryukyus, Okinawa Japan. Before his current appointment, he worked as a post-doctoral fellow/ Assistant/Associate Professor at the Petroleum Institute, Abu Dhabi. He also worked as a Lecturer and Assistant Professor at the Rajshahi University of Engineering & Technology, a premier national engineering university in Bangladesh. He has 24 years of university teaching experience and taught different undergraduate and graduate courses.

His main research interest is focused in the area of energy and heat transfer enhancement, extended surfaces, heat exchangers, heat pipes, vortex generators, flow induced vibrations(FIV), satellite cooling , fouling of heat exchangers in the oil and gas industry, solar powered Stirling engine generator, solar desalination, solar hybrid airconditioning systems, atmospheric water generation etc. During his academic career, Dr. Islam contributed in a book chapter and published more than 150 research papers in Journals and International conferences, including Applied Energy, Applied Thermal Engineering, International journal of Heat and Mass transfer, International Communications in Heat and Mass Transfer, International journal of Mechanical sciences, Renewable Energy, Physics of Fluids, International Journal of Thermal Sciences. Dr. Islam is the recipient of Abu Dhabi National Oil Company (ADNOC) R&D Wisdom Book Award (2012), Japan Govt. Scholarship (Monbukagakusho) Award (2002) and Heiwa Nakajima Foundation (HNF) Tokyo, Japan Scholarship Award (2005). He was the organizing committee member of the Second International ENERGY 2030 Conference, Abu Dhabi, and chaired sessions of ASME-SHTC 2024, GT India ASME 2019 Gas Turbine India Conference, Heat Transfer, Fluid Mechanics and Thermodynamics (HEFAT) International Conference (2016, 2017), ASME-ICOPE-2013, Wuhan, China.

Authors:

Yousuf El Chihabi Khalifa University of Science and Technology
Md. Islam Khalifa University of Science & Technology
Firas Jarrar Al Hussein Technical University
Yap Fatt Khalifa University of Science and Technology